This invention relates to slot antennas and more particularly to a broadband log-periodic slot antenna array.
The use of the log-periodic dipole antenna array for psuedo frequency-independent operation is well known. There are many applications, however, which require a flush-mounted antenna such as one designed for the surface of an aircraft and for these uses the dipole antenna array is not suitable. The slot antenna array is particularly well adapted to such flush-mounted applications since the radiating elements are slots themselves formed in a waveguide wall which may be part of a ground plane constituting the metallic skin of the aircraft.
Log-periodic cavity-backed transverse slot antenna arrays have been proposed in the past in an effort to duplicate the operating characteristics of the dipole counterpart but have met with only limited success. For example, such an antenna is described in an article entitled "A Log-PeriodicCavity-Backed Slot Log-periodic cavity-backed by V. A. Mikenas and P. E. Mayes, 1966 IEEE - PGAP Symposium Digest, Palo Alto, California.